Introducing a New Network Protocol

The AREDN team is introducing a new networking technology into the nightly builds with the ultimate long term goal of replacing OLSR.

OLSR has many faults which AREDN has lived with for a long time. For the last couple of years we’ve been looking at alternatives and making incremental steps in the codebase to allow us to introduce something new. We can finally do that by adding Babel (https://www.irif.fr/~jch/software/babel/) to AREDN.

Babel has a number of qualities which make it good for AREDN. First, it’s a loop free protocol so, regardless of how the network is changing, routing loops will never form in the network. Second, it’s primarily a reactive protocol which sends changes to neighbors when needed rather than broadcasting its state continually. Third, the protocol understands the difference between wired, wireless, and tunneled links –  the three link types AREDN utilizes. Fourth, it’s a layer-3 routing protocol, which integrates easily with how AREDN already operates. Fifth, it’s highly configurable which will allow an optimal setup for our use case. Finally, it’s simple.

We considered a number of options, and another contender was B.A.T.M.A.N. Advanced. Unfortunately this protocol is not a good fit for AREDN as it primarily focuses on level-2 wireless networking. AREDN needs a protocol which can do more. We...